The present invention relates generally to outboard engine mounting brackets. More particularly, this invention pertains to jack plates or jacking plates.
Marine outboard motors (i.e., outboard motors, outboard engines, or outboards) are typically fixed with respect to the transom of a boat. The outboard motor is bolted through holes in the transom or clamped onto the transom via a clamp integral with the outboard motor. Some outboard motors have manual or electric adjustable trim to improve performance of the motor and boat hull combination during varying operating conditions (i.e., speed, hull weight, water conditions, etc.). Jack plates are used with some outboard motors to further improve performance. A jack plate mounts to the boat transom and the outboard motor mounts to the jack plate. The jack plate is used to raise or lower the outboard motor relative to the transom in order to optimize the performance of the outboard motor and hull combination based on varying operating conditions. Additionally, anglers use jack plates to reduce the overall draft of a boat in order to enter and fish very shallow waters while protecting the propeller (i.e., prop) from damage due to contacting the bottom of the waterway or submerged debris. However, if underwater debris, or the bottom is contacted, the prop will be held in fixed relation to the transom and is likely to sustain damage.
Outboard motors and props (i.e., propellers) are susceptible to damage when contacting objects in the water while the boat is under way. Because the outboard motor is mounted to the transom at a fixed angle (generally parallel), striking an underwater object will damage the outboard, prop, and/or transom and hull. In order for hunters and anglers to enter shallow water which is likely to have debris (i.e., submerged stumps, logs, or other objects), kick up plates were developed. Kick up plates allow the outboard to swing up (i.e., increase the angle between the transom and the outboard) in order for the lower unit of the outboard and the prop to rise up over the underwater obstruction, reducing or limiting damage to the outboard, prop, and boat hull. Kick up plates rely on either a spring to bias the engine toward the down (generally parallel to the transom) position or a sheering member which breaks off when a submerged object produced a rearward force on the lower unit of the outboard. Both are insufficient for higher speed operation of boats because they allow the outboard to travel over 90 degrees, potentially putting the prop in contact with a boater operating the outboard via tiller. Additionally, any contact with submerged objects generally requires parts on the kick up plate to be replaced (e.g., sheer pins, springs, etc.).